Can there be too much foreskin?????

Hello everyone,
Well my husband insisted that our son be circumsized so we did have it done shortly after he was born. It was very tramatic for me because I could hear him crying in the other room and I was histerical. As soon as my little boy saw me he clutched close to me and wanted to nurse right away. The nursing comforted him and he soon forgot what was done to him and smiled which gave me some relief. Now my son is 5 months old and it seems like he has too much foreskin. His doctor told me to pull back the foreskin during a diaper change at least once per day and put vasoline around the head of his penis. I have done that and now sometimes when I go to change his diaper his foreskin covers the entire penis. Is it possible that they did not cut off enough skin or is this normal? I assume that as the penis grows longer it will even itself out. This is my first baby and everything is still new to me. Any advice or input from someone who has seen this would be much appreciated.